This invention relates in general to vehicle wheels and in particular to an improved vehicle wheel welding station used to produce such vehicle wheels.
A conventional vehicle wheel is typically of a two-piece construction and includes an inner disc and an outer "full" rim. The disc can be cast, forged, or fabricated from steel, aluminum, or other alloys, and includes an inner annular wheel mounting portion and an outer annular portion. The wheel mounting portion defines an inboard mounting surface and includes a center pilot or hub hole, and a plurality of lug receiving holes formed therethrough for mounting the wheel to an axle of the vehicle. The rim is fabricated from steel, aluminum, or other alloys, and includes an inboard tire bead seat retaining flange, an inboard tire bead seat, an axially extending well, an outboard tire bead seat, and an outboard tire bead seat retaining flange. In some instances, a three-piece wheel construction having a mounting cup secured to the disc is used. In both types of constructions, the outer annular portion of the disc is secured to the rim by welding.
A typical wheel welding station for securing the disc to the rim to produce a steel or aluminum wheel includes a wheel support fixture for supporting the vehicle wheel, and a plurality of welding torches. Typically, for producing automobile and truck vehicle wheels, four torches are provided. However, the number of torches depends upon the particular wheel assembly and/or the welding cycle time which is desired. The wheel support fixture can rotate the wheel relative to torches or, alternatively, the torches can rotate relative to the wheel.
A typical welding torch includes a body having a first end portion and a second end portion. The first end portion is connected to a known cable assembly. The cable assembly contains a welding wire conduit, a gas line conduit, a recirculating cooling water conduit, and an electrical supply cable. The second end portion has a consumable nozzle installed thereon. The nozzle is conventional in the art and includes a contact tip. The welding wire conduit, gas line conduit, and electrical supply conduit all extend from the cable assembly through the torch and to the nozzle. Depending upon whether the nozzle is water cooled, the recirculating cooling water conduit can also extend from the cable assembly through the torch and to the nozzle.
The body of the torch adjacent the second end thereof is bent in a "goose neck" configuration at a predetermined angle to provide a predetermined welding work angle with respect to a selected surface of the vehicle wheel. Typically, for a "bead seat" attached wheel, the body of the torch is bent at an angle of approximately 70.degree. to provide a welding work angle of approximately 20.degree.. For a "well attached" wheel and a "full face" wheel, the body of the torch is bent at an angle of approximately 45.degree. to provide a welding work angle of approximately 45.degree..
When assembling an aluminum wheel, aluminum wire is used and the wire feed conduit constructed from nylon is used to provide a feed path for the aluminum wire. The aluminum wire usually contains surface imperfections, such as burrs, which can create grooves in the inner surface of the nylon conduit or become imbedded into the nylon conduit, especially at the bent portion of the conduit. Thus, as the aluminum wire is fed through the conduit, the grooves impair the feeding of the aluminum wire through the torches and/or imbedded aluminum particles flake off the aluminum as it passes through the conduit creating aluminum shavings which settle in the bent portion and/or contact tip of the respective torches.
During operation of the wheel welding station, the aluminum shavings deposited in bent portion can cause the torches to clog. Once the torches become clogged, the aluminum wire will no longer be able to be fed through the conduit to the end of the torches. As a result, the weld wire extending from the contact tip melts back to and together with the contact tip. This requires stoppage of the wheel welding station so that the contact tip and also, preferably, a new nylon conduit can be installed.
When the welding station is used to weld a steel wheel, steel wire is provided. Unlike aluminum wire, the steel wire can rust. Thus, the steel wire is usually coated with copper or a lubricant to prevent rusting. Also, since the steel wire is much harder than the aluminum wire, the conduit for the steel wire is constructed from steel. The steel wire also usually contains surface imperfections, such as burrs, which can create grooves in the inner surface of the steel conduit, especially at the bent portion of the conduit, or can break off. While clogging of the torch when using steel wire is not as prolific a problem as it is when using aluminum wire, eventually, the contact tip and the wire conduit of the welding station have to be replaced.
It is known to use a single robotically controlled welding torch having a straight body for welding a vehicle wheel for development work.